The costs to produce and utilize hydrogen are extremely high per unit of energy when compared to fossil fuel energy sources such as natural gas or gasoline. The cheapest hydrogen production approaches today are also the most polluting, as they use fossil fuels in even more inefficient ways than cars do. Renewable approaches to hydrogen production are- at best- three times more expensive per unit energy than the cost to produce the same amount of natural gas. The production of hydrogen through biological systems is one area of particularly promising research. There are countless biological systems that produce energy from sunlight, and countless others that produce energy from the metabolism of organic molecules such as glucose. Many microbial organisms produce hydrogen under certain conditions. Optimizing their innate ability to produce hydrogen and developing biohydrogen plants whose economics compete with current commercial plants are key hurdles that must be overcome. Economic models for the production of hydrogen through biological systems are examined in detail in this thesis. The key technical hurdles which drive the capital and production costs are identified. Fruitful areas of potential research are suggested to bring biological hydrogen production to commercial scale as rapidly as possible.